Disable Client Portal in Zoho Books
Here is our approach for disabling client portal in Zoho Books

Approach
It is not possible to disable the client portal but we can remove client from portal
1. Disable portal for Clients one by one
1.1 Open "Customers" module ---->Tap on the customer

1.2 Tap on "More"

1.3 Select "Configure Client Portal" from "More"

1.4 Uncheck the active portal to disable it and save the changes made

2. Disable mail notification in portal (For comments you make during transactions)
2.1 open "Settings"---> Tap on "Preferences"

2.2 Select "Client Portal"

2.3 Uncheck "Send an email notification to my customer when I comment on transactions"

